Mixing devices are used to produce precise and intensive mixtures, for example, for the spinning industry and the non-woven industry. The mixed materials are various chemical fibers, cotton and chemical fibers, various recovered waste fibers, cotton and recovered waste fibers. With high-production weighing cart feeders, in practice, a material cone is produced by means of the pan scale, which is usually arranged centrally above the mixing belt, and leads to a high accumulation of fibers in a short period of time in a multiple number of successively arranged machines. In a disadvantageous manner, defective weighing may arise as a result of weighing containers that are not completely emptied, and material densities that are too high in the center, with disruptions in material transport and in the opening on the downstream mixing roll.
U.S. Pat. No. 7,455,445 B2 discloses a device for mixing fiber components, such as fiber tufts, in particular in spinning preparation, the production of non-wovens or the like, by which the fiber material to be dosed is conveyed in at least two weighing containers, and the fiber material is ejected onto a mixing belt after weighing from the at least two weighing containers. The weighing containers are arranged one behind the other above the mixing belt, viewed in the direction of belt travel. In order to avoid material cones that cause disruptions, the position of at least one weighing container can be adjusted in a location-changing manner transversely to the longitudinal extent of the mixing belt. The disadvantage of this is the high degree of design complexity of the device, which makes it highly error-prone and expensive to manufacture.